Fuel cell follow-up gas supply system and gas supply method

Abstract

The fuel cell follow-up gas supply system comprises a follow-up gas supply valve, the follow-up gas supply valve comprises a valve body and a valve element, and a first cavity and a second cavity are formed in the two sides of the valve element; a third cavity is formed in the first cavity, a valve rod is arranged on the valve element, and the valve rod is in airtight fit with the third cavity; an air channel is formed in the valve element, one end of the air channel communicates with the second cavity, and the other end of the air channel communicates with the third cavity; a valve hole is formed in the bottom of the third cavity, and the end of the valve rod is matched with the valve hole in a closable mode. A spring is arranged between one side of the valve core and the valve body; the valve body is provided with a first gas channel, a second gas channel and a third gas channel which are respectively communicated with the first cavity, the second cavity and the valve hole; and the first gas channel is connected with a regulating valve. The device has the advantages that the structural design is ingenious, the anode gas and the cathode gas can be subjected to follow-up adjustment to ensure that the pressure difference between the anode gas and the cathode gas is maintained in a set range, and the proton exchange membrane is prevented from being damaged.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to a fuel cell follow-up gas supply system and a gas supply method. Background Art

[0002] A fuel cell is a power generation device that converts the chemical energy in the fuel directly into electrical energy by redox reactions with oxygen or other oxidants. The most common fuel is hydrogen, and other fuels can come from any hydrocarbon that can decompose hydrogen, such as natural gas, alcohol, and methane. These batteries have the advantages of high efficiency, environmental friendliness, and high energy density, and are energy power devices with broad development prospects. The fuel cell stack is the core component of the fuel cell system, which is composed of multiple fuel cell monomers stacked in series. The main components include bipolar plates, membrane electrode assemblies, collector plates, insulating plates, and end plates. Among them, the membrane electrode assembly is the core component of the fuel cell, which consists of a proton exchange membrane, a catalyst layer, and a gas diffusion layer. The proton exchange membrane prevents the gas between the anode and cathode from communicating with each other, while only allowing protons to pass through to achieve electron transfer. The catalyst layer promotes the electrochemical reaction between hydrogen and oxygen.

[0003] Existing fuel cells usually use air compressors to increase or decrease the pressure of air, and at the same time increase or decrease the supply of hydrogen. In order to ensure that the pressure difference between air and hydrogen on both sides of the proton exchange membrane is within the allowable range and avoid damage to the proton exchange membrane due to excessive pressure difference, it is usually necessary to use complex algorithms to match and control the air compressor and proportional valve, and it is impossible to achieve follow-up adjustment of the two gases. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is: how to provide a gas supply system and a gas supply method with an ingenious structural design that can dynamically adjust the anode gas and the cathode gas to ensure that the pressure difference between the two is maintained within a set range and avoid damage to the proton exchange membrane.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A fuel cell follow-up gas supply system comprises a follow-up gas supply valve, wherein the follow-up gas supply valve comprises a valve body and a valve core which can be axially moved and airtightly fitted in the valve body, wherein two sides of the valve core form a first cavity and a second cavity separated from each other; a third cavity with a relatively small cross-sectional area is coaxially arranged in the first cavity, the valve core has a valve stem which extends axially into the third cavity, and the valve stem has a sealing portion which airtightly fits with the third cavity; an air channel which is axially arranged in the valve core, one end of the air channel is in communication with the second cavity, and the other end is in communication with the third cavity on a side of the sealing portion which faces away from the second cavity. The bottom of the third cavity has a valve hole arranged opposite to the valve stem, and the length of the valve stem is greater than the length of the third cavity, so that the end of the valve stem can be closed and fitted on the valve hole; a spring is arranged between one side of the valve core and the valve body; the valve body has a first gas channel for connecting a first fluid and a second gas channel and a third gas channel for connecting a second fluid, and the first gas channel, the second gas channel and the third gas channel are connected to the first cavity, the second cavity and the valve hole respectively; the first gas channel is connected to a regulating valve for controlling gas pressure or flow.

[0007] Furthermore, the spring is located in the first cavity, the second cavity or the third cavity.

[0008] Furthermore, there is a gap between the valve stem and the side wall of the third cavity, and the valve stem has a vent hole arranged in the radial direction, and the vent hole is connected to the airway.

[0009] Furthermore, a valve seat is provided at the bottom of the third cavity, and the valve hole is provided on the valve seat.

[0010] Furthermore, the bottom of the first cavity has a cylinder extending toward the valve core, and the third cavity is formed in the cylinder.

[0011] Furthermore, the valve stem has a sealing groove extending in the circumferential direction, and the sealing portion is a first sealing ring arranged on the sealing groove.

[0012] Furthermore, the valve core has a second sealing ring that seals with the valve body.

[0013] Furthermore, at least two second sealing rings are arranged along the axial direction of the valve core.

[0014] Furthermore, it also includes an anode gas supply assembly and a cathode gas supply assembly connected to the fuel cell through a pipeline, and the second gas channel and the third gas channel are connected in series to the anode gas supply assembly or the pipeline of the anode gas supply assembly; the air inlet end of the regulating valve is connected to the pipeline of the cathode gas supply assembly through a pipeline.

[0015] A gas supply method adopts the fuel cell follow-up gas supply system as described above to supply gas.

[0016] In summary, the present invention has the advantages of ingenious structural design, and can perform follow-up adjustment on anode gas and cathode gas to ensure that the pressure difference between the two is maintained within a set range, thereby avoiding damage to the proton exchange membrane, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the structure of the follow-up air supply valve in this embodiment.

[0018] Figure 2 This is a schematic diagram of the force on the valve core. DETAILED DESCRIPTION

[0019] The present invention is further described in detail below in conjunction with embodiments.

[0020] In specific implementation: A fuel cell follow-up gas supply system includes an anode gas supply assembly and a cathode gas supply assembly connected to the fuel cell through a pipeline, and a follow-up gas supply valve, such as Figure 1 As shown, the follow-up air supply valve includes a valve body 1 and a valve core 2 that can be axially moved and airtightly fitted in the valve body 1, and the two sides of the valve core 2 form a first cavity 11 and a second cavity 12 that are separated; a third cavity 13 with a relatively small cross-sectional area is coaxially arranged in the first cavity 11, and the valve core 2 has a valve stem 21 that extends axially into the third cavity 13, and the valve stem 21 has a sealing portion 22 that airtightly fits the third cavity 13; an air channel 23 is axially arranged in the valve core 2, one end of the air channel 23 is communicated with the second cavity 12, and the other end is communicated with the third cavity 13 on the side of the sealing portion 22 away from the second cavity 12; the third cavity 13 The bottom of the valve body 1 has a valve hole 14 arranged opposite to the valve stem 21, and the length of the valve stem 21 is greater than the length of the third cavity 13, so that the end of the valve stem 21 can be closed and fitted on the valve hole 14; a spring 3 is arranged between one side of the valve core 2 and the valve body 1; the valve body 1 has a first gas channel 15 for connecting a first fluid and a second gas channel 16 and a third gas channel 17 for connecting a second fluid, and the first gas channel 15, the second gas channel 16 and the third gas channel 17 are connected to the first cavity 11, the second cavity 12 and the valve hole 14 respectively; the first gas channel 15 is connected to a regulating valve for controlling gas pressure or flow.

[0021] In this embodiment, the valve core 2 has a second sealing ring 25 that seals with the valve body 1, and at least two second sealing rings 25 are arranged along the axial direction of the valve core 2. The bottom of the first cavity 11 has a cylinder 18 extending toward the valve core 2, and the third cavity 13 is formed in the cylinder 18. The bottom of the third cavity 13 is provided with a valve seat 4, and the valve hole 14 is arranged on the valve seat 4. The valve stem 21 has a sealing groove extending along the circumferential direction, and the sealing portion 22 is a first sealing ring arranged on the sealing groove; there is a gap between the valve stem 21 and the side wall of the third cavity 13, and the valve stem 21 has a vent hole 24 arranged in the radial direction, and the vent hole 24 is connected to the airway 23. The spring 3 is located in the first cavity 11 and is coaxially sleeved on the cylinder 18.

[0022] In this embodiment, the second gas channel 16 and the third gas channel 17 are connected in series on the pipeline of the anode gas supply assembly; specifically, the anode gas supply assembly is connected to the third gas channel 17 through a pipeline, and the second gas channel 16 is connected to the fuel cell through a pipeline. The cathode gas supply assembly is connected to the regulating valve through a pipeline, and the regulating valve is connected to the first gas channel 15 and the fuel cell through a tee.

[0023] In this embodiment, high-pressure anode gas enters the third cavity 13 from the second gas channel 16 via the valve hole 14 and then enters the second cavity 12 through the gas channel 23 in the valve core 2. At the same time, cathode gas enters the first cavity from the first gas channel 15.

[0024] At this time, the force on the valve core 2 is as follows: Figure 2 As shown, the gas pressure at the valve hole 14 is P 入 , the corresponding action area is S 入 ; The gas pressure in the first cavity is P 空 , the corresponding action area is S 空 , the spring force in the first cavity is F 弹 ; The gas pressure in the second cavity is P 出 , the corresponding action area is S 出 ; S 出 =S 入 +S 空 The force balance relationship of valve core 2 is as follows:

[0025] P 出 S 出 =P 入 S 入 +P 空 S 空 +F 弹

[0026]

[0027] Usually, in order to reduce P 入 Changes in P 出 The influence of the valve core S 入 The cross-sectional area of ​​the valve hole 14 is matched. Since the valve hole 14 is a throttling hole, its cross-sectional area is very small. The ratio is close to 1. The ratio is close to 0, and the above formula can be approximated as:

[0028]

[0029] At this time, the cathode gas pressure delivered to the fuel cell (i.e., P 空 ) and the anode gas pressure delivered to the fuel cell (i.e., P 出 ) (i.e. the pressure difference on both sides of the membrane) is:

[0030]

[0031] In the above formula, F 弹 The value of is related to the deformation and elastic coefficient of the spring. The elastic coefficient remains unchanged, while the deformation of the valve core can be almost ignored under the pressure balance state, that is, can be approximated as a constant.

[0032] In this way, no matter the pressure P in the first cavity 11 空 Increase or decrease, the output pressure P of the second chamber 出 The pressure between the two can always be maintained within a set range, thus achieving follow-up adjustment.

[0033] During the operation of the fuel cell, even if the hydrogen supply pressure fluctuates, as long as the hydrogen input pressure is greater than the required output pressure, the follow-up valve in this embodiment can always maintain the pressure difference on both sides of the membrane within the set value range, thereby avoiding pressure damage to the membrane, which is beneficial to extending the service life, simplifying the control system and saving costs.

[0034] In specific implementation, the user can adjust the effective area S of the valve core 2 according to the system control requirements. 入 , S 空 and S 出 , and the elastic coefficient of the spring can be designed so that the gas pressure in the second cavity can change with the gas pressure in the first cavity, and the pressure difference between the two can be maintained within the set pressure difference range.

[0035] It should be noted that the spool-up valve of this embodiment can be applied not only to the fuel cell of this embodiment, but also to other fluid spool-up control scenarios where the pressure difference between two paths needs to be controlled to remain within a set range.

[0036] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A fuel cell follow-up gas supply system, characterized in that: The invention comprises a follow-up air supply valve, the follow-up air supply valve comprises a valve body (1) and a valve core (2) which is axially movable and airtightly fitted in the valve body (1), the two sides of the valve core (2) forming a first cavity (11) and a second cavity (12) which are separated; a third cavity (13) with a relatively small cross-sectional area is coaxially arranged in the first cavity (11), the valve core (2) has a valve stem (21) which extends axially into the third cavity (13), the valve stem (21) has a sealing portion (22) which airtightly fits with the third cavity (13); an air passage (23) is axially arranged in the valve core (2), one end of the air passage (23) is communicated with the second cavity (12), and the other end is communicated with the third cavity (13) on the side of the sealing portion (22) facing away from the second cavity (12); the third cavity The bottom of the body (13) is provided with a valve hole (14) arranged opposite to the valve stem (21); the length of the valve stem (21) is greater than the length of the third cavity (13), so that the end of the valve stem (21) can be closed and fitted on the valve hole (14); a spring (3) is arranged between one side of the valve core (2) and the valve body (1); the valve body (1) is provided with a first gas channel (15) for connecting a first fluid and a second gas channel (16) and a third gas channel (17) for connecting a second fluid; the first gas channel (15), the second gas channel (16) and the third gas channel (17) are respectively connected to the first cavity (11), the second cavity (12) and the valve hole (14); the first gas channel (15) is connected with a regulating valve for controlling gas pressure or flow.

2. The fuel cell follow-up gas supply system according to claim 1, characterized in that: The spring (3) is located in the first cavity (11), the second cavity (12) or the third cavity (13).

3. The fuel cell follow-up gas supply system according to claim 1, characterized in that: There is a gap between the valve stem (21) and the side wall of the third cavity (13), and the valve stem (21) has a vent hole (24) arranged in the radial direction, and the vent hole (24) is connected to the air channel (23).

4. The fuel cell follow-up gas supply system according to claim 1, characterized in that: A valve seat (4) is provided at the bottom of the third cavity (13), and the valve hole (14) is provided on the valve seat (4).

5. The fuel cell follow-up gas supply system according to claim 1, characterized in that: The bottom of the first cavity (11) has a cylinder (18) extending toward the valve core (2), and the third cavity (13) is formed in the cylinder (18).

6. The fuel cell follow-up gas supply system according to claim 1, characterized in that: The valve stem (21) is provided with a sealing groove extending in the circumferential direction, and the sealing portion (22) is a first sealing ring provided on the sealing groove.

7. The fuel cell follow-up gas supply system according to claim 1, characterized in that: The valve core (2) is provided with a second sealing ring (25) which is in sealing cooperation with the valve body (1).

8. The fuel cell follow-up gas supply system according to claim 7, characterized in that: At least two second sealing rings (25) are arranged along the axial direction of the valve core (2).

9. The fuel cell follow-up gas supply system according to any one of claims 1 to 8, characterized in that: It also includes an anode gas supply assembly and a cathode gas supply assembly connected to the fuel cell through a pipeline, the second gas channel (16) and the third gas channel (17) are connected in series to the anode gas supply assembly or the pipeline of the anode gas supply assembly; the air inlet end of the regulating valve is connected to the pipeline of the cathode gas supply assembly through a pipeline.

10. A gas supply method, characterized in that: Gas is supplied by using the fuel cell follow-up gas supply system as described in any one of claims 1 to 9.

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